The present invention pertains to a binding-in and pressing machine for the joint forming and pressing-in of book blocks cased in book cases.
After casing-in the book block into the book case, a crease-free and permanent bond between the end sheets of the book block and the inner sides of the book is achieved by pressing-in the book. In industrial bookbinding, this full-surface pressing step is carried out on so-called binding-in and pressing machines together with the joint forming process, in which the book case joints are formed and glued.
For example, U.S. Pat. No. 2,921,322 describes a book pressing and joint forming machine that is assembled into a production line together with a casing-in machine. The book pressing and joint forming machine comprises a plurality of pressing stations that are arranged in a straight row and equidistantly spaced apart from one another, wherein each pressing station contains a pair of press plates that lie opposite of one another and serve for exerting pressure upon the sides of a book, and wherein the distance between the opposing press plates is adjustable. Pairs of oppositely arranged and heated joint forming rails are assigned to the pressing stations and realized adjustably with respect to their mutual distance in order to form the book case joints.
The joint forming rails are situated on a reciprocating carriage and simultaneously serve as a transport means for advancing the books from station to station in a cyclic fashion, wherein the joint forming rails subsequently return into their starting position in order to receive and advance another book. Devices as they are known, for example, from DE 92 13 920 U1 are used for aligning a cased-in book in order to carry out the pressing-in and joint forming steps. Such an alignment device comprises a forming bridge for supporting a rounded book, a former for pressing the book block into the book case spine being supported on the forming bridge and alignment means that act upon the front edge of the book case. The thusly aligned book is transported into the first pressing station by means of a first transport means in the form of narrow press jaws that act in lateral regions near the joints and are arranged on the carriage, wherein the book is initially full-surface pressed above these press jaws by the press plates of this first pressing station, and wherein the joint forming of the book case is subsequently carried out during the additional transport by means of a first pair of joint forming rails. Due to the broad spectrum of book formats to be processed as well as the various shapes of book spines, the numerous forming bridges required need to be interchanged with corresponding frequency.
DE 12 07 334 B claims a binding-in and pressing machine that acts upon a series of books and comprises a rotor that is movable about a vertical axis, wherein a plurality of pressing devices that respectively comprise one pair of opposing press plates is arranged on the periphery of said rotor. The rotor intermittently moves the pressing devices into successive pressing stations equipped with joint forming devices that respectively consist of a pair of opposing joint forming jaws. During the cyclic transport of the books through the individual processing stations, the pressure exerted upon the sides of the book is maintained and the joint forming device is closed in the respective stations in order to form the book case hinges and to transmit heat to these regions. In order to insert the books into the pressing devices, a book standing on its spine is raised between the press plates by means of a T-shaped lift carriage, wherein the book is taken hold of and clamped in position by said press plates. In the ensuing station, the press plates are opened such that the pressure exerted upon the book block via the book case is diminished. The book is now (pre-)formed by pressing one forming rail against the;; front edge cut of the book block such that the book block is pressed against the book case spine, wherein the joint forming jaws engage into the book case joints and thusly prevent the entire book from sliding downward.
According to one additional development of this binding-in and pressing machine, the joint forming devices are arranged on and actuated in the same cycle with the pressing devices. The joint forming jaws therefore can remain closed during the rotation such that more time is available for heat to act upon the book case material. A machine according to this additionally developed concept is known from DE 44 22 783 A1, wherein the books are raised into the pressing devices with a loading table that contains prism rails for linearly supporting the book spines in this case. A punch is lowered onto the front edge cut of the book block in the same infeed station as soon as the joint forming jaws are closed and only a slight pressure, if any, is exerted upon the book by the press plates. The cycle of the rotor can only continue once the punch is moved out of the clamping region of the press plates. The cycle capacity of this particular construction is limited due to the numerous and partially very time-consuming functional steps in the infeed station, as well as the limited rotational dynamics of the rotor caused by the high forces of inertia. Although an increase in capacity can be achieved with this pair-by-pair arrangement of the pressing devices on the rotor, this type of arrangement is associated with a substantial additional expenditure for two parallel streams of books, particularly in the infeed and delivery regions of the machine.